Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (549,934)	$ 100,185
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Asset impairment	630,641	5,624
Depreciation, depletion and amortization	82,676	49,618
Distributions from equity earnings from unconsolidated investment	34,545	32,225
Equity earnings from unconsolidated investment	(36,739)	(28,865)
Gain on reserve swap	(9,290)	(5,690)
Other, net	(3,033)	2,142
Other, net—affiliates	(721)	0
Change in operating assets and liabilities:
Accounts receivable	11,919	(5,072)
Accounts receivable—affiliates	2,044	(2,881)
Accounts payable	(2,769)	1,662
Accounts payable—affiliates	1,616	94
Accrued liabilities	3,059	993
Deferred revenue	6,035	(81)
Deferred revenue—affiliates	(3,399)	11,426
Accrued incentive plan expenses	(6,417)	(5,445)
Other items, net	1,750	750
Other items, net—affiliates	(633)	411
Net cash provided by operating activities	161,350	157,096
Cash flows from investing activities:
Acquisition of mineral rights	(35,939)	(14,035)
Acquisition of plant and equipment and other	(8,581)	(207)
Proceeds from sale of plant and equipment and other	11,006	5
Proceeds from sale of mineral rights	6,941	0
Return on equity and other unconsolidated investments	0	3,633
Return on long-term contract receivables—affiliate	2,121	910
Net cash used in investing activities	(24,452)	(9,694)
Cash flows from financing activities:
Proceeds from loans	100,000	2,000
Proceeds from issuance of common units	0	24,826
Capital contribution by general partner	0	507
Repayment of loans	(151,175)	(69,175)
Distributions to partners	(66,142)	(118,372)
Distributions to non-controlling interest	(2,744)	(974)
Debt issuance costs and other	(5,757)	(601)
Net cash used in financing activities	(125,818)	(161,789)
Net increase (decrease) in cash and cash equivalents	11,080	(14,387)
Cash and cash equivalents at beginning of period	50,076	92,513
Cash and cash equivalents at end of period	61,156	78,126
Supplemental cash flow information:
Cash paid during the period for interest	57,917	52,266
Plant, equipment and mineral rights funded with accounts payable or accrued liabilities	$ 4,465	$ 0